JPH07226621A - Offset parabolic antenna polarization plane adjusting mechanism - Google Patents

Abstract

PURPOSE:To obtain an offset parabolic antenna polarization plane adjusting mechanism capable of adjusting the angle of the polarization plane of a power feeding part without the need of a dangerous operation. CONSTITUTION:By loosening a long bolt 9 and rotating an offset parabolic antenna 10 around a strut, the azimuth angle is adjusted. By loosening a bolt 4-3 and an adjustment bolt 4-2 and vertically rotating the offset parabolic antenna 10 around the bolt 4-3, an elevation angle is adjusted. By loosening the adjustment bolt 3-2 and the bolt not shown in the figure and rotating the offset parabolic antenna 10 around the bolt not shown in the figure and a radio wave arriving direction, a polarization angle is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarization plane adjusting mechanism for an offset parabolic antenna that receives linearly polarized waves, and is particularly suitable for application to an offset parabolic antenna that receives CS broadcasting.

[0002]

2. Description of the Related Art Satellite broadcasts are currently classified into BS broadcasts and CS broadcasts, of which BS broadcasts use right-hand circular polarization, but CS broadcasts use linear polarization. Further, in order to increase the number of channels, orthogonal polarization composed of vertical polarization and horizontal polarization is used. As shown in FIG. 4, the communication satellite in satellite broadcasting is pre-inclined by 30 degrees with respect to north and south so that the vertical / horizontal planes on the ground and the vertical / horizontal polarization planes of the radio waves substantially match. However, due to the relative position between the communication satellite 100 and the position of the receiving point, a certain angle difference occurs in the angle of the polarization plane. This angle difference is called a polarization angle, and the polarization angle varies depending on the region as shown in FIG. By the way, if the polarization plane of the reception antenna 200 does not match the polarization plane of the satellite broadcast, the degree of polarization discrimination decreases, and a signal from an undesired polarization leaks as noise. For this reason, the angle of the reception polarization plane of the reception antenna 200 that receives the CS broadcast is determined by the incoming C
It is necessary to match the angle of the polarization plane of S broadcasting.

Looking at the polarization angle in the case of the communication satellite JCSAT-2, the deviations of the polarization angles are opposite in the north direction and the south direction, and as shown in FIG. It becomes a negative angle, and it becomes a positive angle from Kyushu to Honshu and Hokkaido. Therefore, the CS antenna adjusts the angle of the polarization plane of the reception so that the CS antenna is
To be able to receive the broadcast is a necessary structure for the receiving antenna. Therefore, conventionally, a CS antenna capable of adjusting the angle of the reception polarization plane as shown in FIG. 7 has been proposed. This CS antenna is an offset parabolic antenna. Before the description of FIG. 7, the offset parabolic antenna will be briefly described with reference to FIG.

In FIG. 6 (a), in the parabolic antenna 300 having a shape of a large parabola indicated by a broken line and having a rotationally symmetric shape, it is necessary to dispose the primary radiator at the focal position thereof, but the primary radiation is provided in front of the reflecting mirror. If the device and its power supply line are provided, it interferes with the passage of radio waves and causes deterioration of radiation characteristics. Therefore, in order to avoid this, an antenna in which a non-rotationally symmetric mirror surface is used and a primary radiator is provided outside the aperture is an antenna called an offset antenna. That is, a part of the parabolic antenna 300 shown in FIG. 6A is cut off as shown by a solid line to form a mirror surface which is not rotationally symmetric, which is an offset parabolic antenna and has a shape shown in FIG. . As shown in this figure, the offset parabolic antenna can be a low sidelobe antenna because there is no obstacle such as a primary radiator between the reflecting mirror 101 and the incoming radio wave indicated by the arrow.

Such an offset parabolic reflector 10
7 shows the state in which No. 1 is attached to the column 105,
In this figure, CS broadcasting from a communication satellite is reflected and focused by a reflector 101 of an offset parabolic antenna,
The signal is received by the feed horn 102 arranged at the focal position. The feed horn 102 is composed of a conical horn having a circular cross section.
After that, the circular waveguide 103 and the converter unit 111 are provided to form the power feeding unit 104. Then, the CS-IF signal down-converted by the frequency converter unit 111 of the power feeding unit 104 is transmitted from the power feeding unit 104 to the CS tuner installed in the house by the coaxial cable.

The offset parabolic reflecting mirror 101 is fixed to a column 105 by a mounting member 106 so that the mounting elevation angle and azimuth angle can be adjusted. This prop 1
Reference numeral 05 is firmly fixed to a veranda or the like by a fitting not shown. The power feeding unit 104 is positioned at the focal point of the offset parabolic reflecting mirror 101 by the arm 107 fixed to the mounting member 106, and is rotatably fixed by loosening the polarization adjusting screw 113. In order to install the CS antenna configured as described above, first, the offset parabolic reflector 10
1 is fixed to the pillar 105 by the mounting bracket 106 while finely adjusting the elevation angle and the azimuth angle toward the direction of the communication satellite. Next, the polarization adjusting screw 113 is loosened, and the power feeding unit 1
By rotating 04, the angle of the plane of polarization of the power feeding unit 104 is adjusted so as to match the angle of the plane of polarization of the CS broadcast, so that the CS broadcast can be received.

[0007]

However, as shown in FIG. 7, since the power feeding section 104 is arranged at the focal position of the offset parabolic reflector 101, the CS
In order to adjust the angle of the plane of polarization of the power feeding unit 104 when the antenna is installed, there is a problem that it is necessary to lean out from the veranda, which requires extremely dangerous work. Therefore, an object of the present invention is to provide an offset parabola antenna polarization plane adjustment mechanism that can adjust the angle of the polarization plane of the power feeding section without requiring dangerous work.

[0008]

In order to achieve the above object, an offset parabola antenna polarization plane adjusting mechanism of the present invention is arranged so that when the elevation angle and azimuth angle of the offset parabola antenna are matched with the radio wave arrival direction, the radio wave arrival A first polarization adjusting fitting having an orthogonal flat surface formed so as to be orthogonal to the direction on one surface, and an adjustment flat surface rotatably fixed while rubbing against the orthogonal flat surface of the first polarization adjusting fitting. And a second polarization adjusting fitting provided on the front surface, the first polarization adjusting fitting is fixed to the back surface of the offset parabolic antenna, and the adjustment plane is rotated with respect to the orthogonal plane, The polarization plane of the offset parabolic antenna is adjusted.

The offset parabola antenna polarization plane adjusting mechanism of the present invention secures the strut mounting metal fitting so as to sandwich the extending portion extending rearward from both sides of the second polarization adjusting metal fitting, and the strut mounting metal fitting. On the other hand, the elevation angle of the offset parabolic antenna is adjusted by changing the mounting angle of the extending portion.

[0010]

According to the present invention, since the polarization adjusting metal fitting for adjusting the angle of the polarization plane of the offset parabolic antenna is fixed to the back surface of the offset parabola antenna, the angle of the polarization plane can be adjusted in a short time without any dangerous adjustment work. You will be able to easily adjust.

[0011]

1 is a general view of an offset parabolic antenna 10 equipped with an offset parabolic antenna polarization plane adjusting mechanism of the present invention. In this figure, an offset parabolic antenna 10 is composed of a reflecting mirror 1, a feed horn 7 arranged at a focal position of the reflecting mirror 1, and an arm 6 fixing the feed horn 7 at a predetermined position.
On the back surface of the offset parabolic antenna 10, the offset parabolic antenna 10 is fixed to a support, and a fixture that can orient the offset parabolic antenna 10 in the direction of arrival of radio waves is fixed.

This fixture is a polarization adjusting metal fitting A2 which has an orthogonal plane plate which is orthogonal to the direction of arrival of radio waves and which is inclined by an angle θ with respect to the opening surface of the reflecting mirror 1, and this polarization adjusting metal fitting A2. Of the polarization adjustment fitting B3 rotatably attached to the orthogonal plane plate of No. 2 and the extension portion of the polarization adjustment fitting B3, and the other end of the support attachment fitting A5 for holding the support pillar. The offset parabola antenna polarization plane adjusting mechanism of the present invention is composed of
It is composed of a polarization adjusting fitting A2 and a polarization adjusting fitting B3. Next, a mechanism for orienting the offset parabolic antenna 10 in the direction of arrival of radio waves using a fixture will be described with reference to the perspective view shown in FIG. 2 and the development view shown in FIG.

The column 8 for supporting the offset parabolic antenna 10 is sandwiched between the other end of the column mounting bracket A4 and the column mounting bracket B5, and a long bolt 9 connecting the column mounting brackets A4 and B5 is fastened. By doing so, the column mounting bracket A4 and the column mounting bracket B5 are firmly attached to the column 8. Further, a long hole 4-1 and a bolt insertion hole are provided in a side plate 4-4 of the U-shaped portion provided on one surface of the column mounting bracket A4, and the bolt 4 is inserted in this bolt insertion hole.
-3 and insert the adjusting bolt 4-2 into the long hole 4-1.
Insert the bolt 4-3 and the adjustment bolt 4-2 into the bolt attachment portion 3-5 (see FIG. 3) provided on the extension portion 3-4 of the polarization adjusting fitting B3, and tighten the tips of the adjustment bolt 4-2. As a result, the polarization adjusting bracket B3 is fixed to the column mounting bracket A4 so that the mounting angle can be adjusted.

Further, the adjusting flat plate 3 of the polarization adjusting fitting B3
-3 (see FIG. 3) is formed with a long hole 3-1 and a bolt insertion hole (not shown), and the long hole 3-1 and the bolt insertion hole are respectively provided with adjustment bolts 3-2 and not shown. When the bolts are inserted and the other ends of both bolts are fastened to the orthogonal flat plate 2-1 of the polarization adjusting fitting A2, the polarization adjusting fitting A2 is fixed to the polarization adjusting fitting B3 so that the mounting angle can be adjusted. Has been done.

Further, the polarization adjusting fitting A2 is fixed to the center of the back surface of the reflecting mirror 1 of the offset parabolic antenna 10, but the orthogonal flat plate 2- formed on the polarization adjusting fitting A2.
As shown in FIG. 3, 1 is tilted, for example, by (90 ° -θ), and as a result, as shown in FIG. 1, the arrival direction of the radio wave and the orthogonal plane plate 2-1 are orthogonal to each other. That is,
By rotating the reflecting mirror 1 of the offset parabolic antenna 10 with the vertical line of the orthogonal flat plate 2-1 as a rotation axis, the reception polarization plane of the offset parabolic antenna 10 can be adjusted. The polarization adjusting metal fitting A is attached to the adjustment flat plate 3-3 in which the elongated hole 3-1 of the polarization adjusting metal fitting B3 is formed.
While rubbing the orthogonal plane plate 2-1 formed by 2,
This is done by rotating the inside of the long hole 3-1 so that the adjusting bolt 3-2 moves, so that the mounting angle can be adjusted.

In the fixture constructed in this manner, the long bolt 9 is loosened and the offset parabolic antenna 10 is rotated about the support column to adjust the azimuth angle and temporarily fix the long bolt 9. Next, bolt 4-3
By loosening the adjustment bolt 4-2 and rotating the offset parabola antenna 10 up and down about the bolt 4-3, the adjustment bolt 4-2 moves in the elongated hole 4-1 to move the offset parabola. The elevation angle of the antenna 10 is adjusted. Then, the bolt 4-3 and the adjusting bolt 4-2 are temporarily fixed. Next, the adjustment bolt 3-2 and the bolt (not shown) are loosened, and the offset parabola antenna 10 is rotated about the bolt (not shown) around the radio wave arrival direction as an axis, so that the inside of the elongated hole 3-1 is adjusted by the adjustment bolt 3-2. Moves, and its plane of polarization is adjusted. Then, the bolt and the adjusting bolt 3-2 (not shown) are temporarily fixed. By repeating the above operation and tightening each bolt, the azimuth angle, the elevation angle, and the plane of polarization of the offset parabolic antenna 10 can be matched with the direction and the plane of polarization of the incoming radio wave, so that the best reception can be performed. Become.

As described above, according to the polarization parabolic plane adjusting mechanism of the present invention, the adjustment of the azimuth angle, the elevation angle and the polarization angle can be performed from the back side of the offset parabola antenna. Can be done safely without In addition, since the azimuth angle, the elevation angle, and the polarization angle are determined in advance by the receiving point, the elevation angle is engraved along the long hole 4-1 and the long hole 3-
By engraving the angle of the plane of polarization along the line 2, workability can be further improved.

[0018]

Since the present invention is configured as described above, the polarization adjusting metal fitting for adjusting the angle of the polarization plane of the offset parabolic antenna can be fixed to the back surface of the offset parabolic antenna, which is a dangerous adjustment work. It is possible to easily adjust the angle of the polarization plane of the offset parabolic antenna in a short time without involving.

[Brief description of drawings]

FIG. 1 is an overall view of an offset parabolic antenna equipped with an offset parabolic antenna polarization plane adjusting mechanism of the present invention.

FIG. 2 is a perspective view of a fixture including an offset parabolic antenna polarization plane adjusting mechanism of the present invention.

FIG. 3 is a development view of an offset parabolic antenna polarization plane adjusting mechanism of the present invention.

FIG. 4 is a diagram illustrating a polarization angle in CS broadcast reception.

FIG. 5 is a diagram showing a tilt angle of a polarization angle depending on a reception point.

FIG. 6 is a diagram showing the principle of an offset parabolic antenna.

FIG. 7 is a diagram showing a conventional CS broadcast receiving antenna.

[Explanation of symbols]

 1 Reflector 2 Polarization adjustment metal fitting A 2-1 Orthogonal plane plate 3 Polarization adjustment metal fitting B 3-1 and 4-1 Long hole 3-2 and 4-2 Adjustment bolt 3-3 Adjustment plane plate 3-4 Extension part 3-5 Bolt mounting portion 4 Strut mounting tool A 4-3 Bolt 4-4 Side plate 5 Strut mounting bracket B 6,107 Arm 7,102 Feed horn 8,105 Strut 9 Long bolt 10 Offset parabolic antenna 100 Communication satellite 101 Offset parabola Reflector 103 Circular waveguide 104 Feeding unit 106 Mounting bracket 111 Converter 113 Polarization adjusting screw 200 Receiving antenna 300 Parabolic reflector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Yoshi ▼ Mamoru Ta, 4-7-4 Kitamachi, Warabi-shi, Saitama, Japan Atena Co., Ltd. Warabi factory

Claims (2)

[Claims] Claim: What is claimed is: 1. A first polarization adjusting fitting having an orthogonal plane formed on one surface thereof so as to be orthogonal to the radio wave arrival direction when the elevation angle and the azimuth angle of the offset parabolic antenna are matched with the radio wave arrival direction. And a second polarization adjusting fitting provided on the front surface thereof with an adjusting flat surface rotatably fixed while rubbing against the orthogonal plane of the first polarization adjusting fitting, and on the back surface of the offset parabolic antenna, An offset parabolic antenna polarization plane adjusting mechanism, characterized in that the polarization plane of the offset parabolic antenna is adjusted by fixing the first polarization adjusting fitting and rotating the adjustment plane with respect to the orthogonal plane. . 2. A strut mounting metal fitting is fixed so as to sandwich an extending portion extending rearward from both sides of the second polarization adjusting metal fitting, and a mounting angle of the extending portion is variable with respect to the strut mounting metal fitting. An offset parabolic antenna polarization plane adjusting mechanism for adjusting the elevation angle of the offset parabolic antenna.